Tobacco smoking is known to be linked with serious respiratory, heart, and neoplastic diseases. In 2010, the United States Surgeon General reported that annually, approximately one in every five deaths (443,000) in the United States was due to cigarettes. A large proportion of these deaths were caused by early heart attacks, chronic lung diseases, and cancers, which impose an economic burden of about $193 billion, annually, in health care costs and loss of productivity.
Tobacco smoke is an extremely complex mixture of about 6000 chemical compounds, which can be divided into two phases: a particulate phase, which is commonly called tar; and a vapor phase, which contains gases and semi-volatile compounds. About 4800 compounds have been identified in the tar portion of cigarette smoke and about 69 of these have been identified as carcinogens. At least 28 chemicals in smokeless tobacco have been found to cause cancer. The most harmful chemicals in smokeless tobacco are tobacco-specific nitrosamines, which are formed during the growing, curing, fermenting, and aging of tobacco. The level of tobacco-specific nitrosamines varies by product. Scientists have found that nitrosamine level is directly related to the risk of cancer. In addition, using smokeless tobacco may also cause heart disease, gum disease, and oral lesions.
Despite the dangers, many people persist in using tobacco products because of their addiction to nicotine, which constitutes about 0.6-3.0% of the dry weight of tobacco. In fact, nicotine dependence is higher than that of any other substance abuse disorder.
It would, therefore, be desirable to have a tobacco substitute that satiates a nicotine craving while minimizing exposure to the harmful compounds found in tobacco.